Newbro's Herpicide was invented by Mr. Dupont Newbro from Butte, Montana, who set up a drug store in 1891. In 1898, Newbro believed that parasites caused dandruff and then hair loss, ultimately leading to baldness. Newbro called his treatment "herpicide," probably from the Latin term herpes, meaning "creep," and "cide," meaning death.

This might seem a bit hooky now, but at the time, scientists attributed dandruff and a host of other skin conditions to Malassezia (a species of yeast). Newbro used the work of noted dermatologist Raymond Sabourand from the Pasteur Institute in Paris to back his product. Sabourand specialized in fungi that cause skin diseases in animals. One study of rabbits that went bald soon after being innoculated with the human dandruff 'germ' can be seen in this ad for the herpicide: Rabbit ad.